In known engines of this type, for example LOX-LH2 or LOX-kerosene engines currently used in launchers, the oxidizer propellant and fuel propellant are injected separately into the combustion chamber of said engines, the mixing of said propellants taking place in said combustion chamber.
Owing to the fact that, in these known engines, it is difficult to cause relatively large pressure variations in the propellant feeds without modifying the ratio of the propellants in the mixture thereof, the possible adjustment in thrust caused by such variations in feed pressure is relatively small. In practice, it is barely possible to obtain a thrust adjustment of around 10 to 20%.